SYN439: Synthesizing Apirin section date Data Sheet l Synthesizing Aspirin 2.1o9
ID: 580616 • Letter: S
Question
SYN439: Synthesizing Apirin section date Data Sheet l Synthesizing Aspirin 2.1o9 mass of salicylic acld, 9 mass of acetic anhydride, g (density -1.08 g mL-1) number of moles of salicylic acid (GMM- 138 g mor) number of moles of acetic anhydride (GMM = 102 g mor) limiting reagent mass of filter paper, g mass of watch glass, g mass of filter paper and watch glass, g mass of aspirin crystals, filter paper, and watch glass, g actual yield of aspirin, g theoretical yield of aspirin (GMM: 180 g mor'). percent yield, % Testing Your Synthesized Aspirin 2.2469 . 55-354 57.5 75 Il. observations salicylic acid+ ethanolic FeClh solution aspirin + ethanolic FeCl3 solution ethanolic FeCly solution conclusion based upon above observations observations of heated synthesized aspirin Ill. Treating the Discarded Reaction Mixtures and solution after adding phenolphthalein solution name and molarity of solution used to neutralize Rinses Solution for Disposal initial color of "Discarded Reaction Mixtures and Rinses "Discarded Reaction Mixtures and Rinses' solutionExplanation / Answer
1. Synthesis of aspirin from salicylic acid
salicylic acid + acetic anhydride ---> aspirin + acetic acid
starting mass of salicylic acid = 2.104 g
moles of salicylic acid present = mass/molar mass
= 2.104 g/138 g/mol
= 0.01525 mol
moles of acetic anhydride required = 0.01525 mol
mass of acetic anhydride needed = moles x molar mass
= 0.01525 mol x 102 g/mol
= 1.555 g
volume of acetic anhydride needed = mass/density
= 1.555 g/1.08 g/ml
= 1.44 ml
1 mole of salicylic acid reacts to form 1 mole of aspirin product
moles of aspirin formed = 0.01525 mol
Theoretical mass of aspirin produced = moles x molar mass
= 0.01525 mol x 180.157 g/mol
= 2.75 g
Actual yield of aspirin not given above
percent yield = (actual yield of aspirin/theoretical yields of aspirin) x 100
II. Testing synthesized aspirin
Salicylic acid + FeCl3 solution : It reacts to form Fe compound which gives a purple color.
FeCl3 is a specific reagent to test for the presence of free phenolic -OH group.
Aspirin + FeCl3 solution : Aspirin does not have any free -OH group of phenol and therefore this reaction gives no color change.
If however, we had salicylic acid impurity present in aspirin sample, we would get light pink coloration.
This test can be used to define purity of the prepared aspirin sample.
III. discarding reaction mixture.
The reaction mixture would be colorless in solution due to presence of acetic acid after addition of phenolphthalein indicator.
The solution before discarding can be neutralized with 1 M NaOH solution to make it neutral and then may be discarded in proper waste container.
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